【作者】 张斌；

【导师】 任自艳； 刘世勋；

【作者基本信息】 沈阳工业大学 ， 电气工程， 2025， 硕士

【摘要】 轴向磁通永磁(Axial Flux Permanent Magnet,AFPM)电机高转矩密度和结构紧凑的特点使其成为近年来电机领域研究的热点。AFPM电机拓扑结构非常丰富,其中定子无轭型(Yokeless and Segmented Armature,YASA)电机因缺少轭部能提高电机转矩密度和材料利用率而受到追捧。但是,由于YASA结构的特殊性,在工程中仍存在一些急需解决的问题,如更高效的磁路设计、更高效的分析方法、多目标优化设计、结构设计与强度计算、散热问题等。基于AFPM电机存在的上述问题,本文主要从以下四个方面开展研究工作:首先,研究YASA结构AFPM电机的电磁设计方案。利用轴向电机尺寸公式计算电机内径和外径;根据绕组系数、绕组分布对称性、齿槽转矩等理论确定16P18S和20P18S两种不同的极槽配合;通过YASA结构定子尺寸公式和绕组公式计算定子铁心尺寸和绕组参数;研究Halbach阵列、内置式和表贴式三种不同的转子结构,确定永磁体极弧系数取值范围;在电机气隙长度和内、外径比值选定的前提下,基于16P18S电磁方案的空载和负载性能证明AFPM电机二维分析方法对三维分析方法具有近似代替性。其次,分析两种极槽配合下电机的反电动势、齿槽转矩、电流密度和转子铁心厚度,确定最优的极槽配合;借助拉丁超立方取样方法对最优极槽配合槽口宽度、永磁体极弧系数、转子铁心厚度、气隙长度等参数进行敏感性分析,建立反电动势、转矩和齿槽转矩的响应面模型,通过进化算法实现反电动势、转矩、齿槽转矩和电机电流密度的多目标性能优化。然后,设计YASA电机零、组件结构。根据转轴刚度和强度公式计算转轴的最小轴径,通过改变转轴结构参数降低键槽的应力,通过在轴肩位置设置圆角减缓应力集中现象;选定PEEK材料制作定子支架,基于电机气隙不对称现象验证该材料的可靠性,建立定、转子支架形变的归一化模型并结合气隙不均匀度确定定、转子支架尺寸;设计过渡零件和端盖的结构形式完成电机的总装设计。最后,分析和改进电机的散热能力。通过计算电机定子铁心、定子绕组和转子三部分的损耗确定电机的热源;基于流-固耦合原理对圆形水管沿定子外圈环绕的冷却结构进行仿真计算,根据电机温度分布规律将圆形水管改进为两种不同的异型(正方形)水管并紧贴定子绕组环绕分布,通过对比两种结构下定子温度分布和水管进出口压力,在考虑经济性和实用性的前提下选择冷却效果最佳的水管结构。更多还原

【Abstract】 Axial flux permanent magnet(AFPM)motor has become a research hotspot in the field of motor in recent years due to its high torque density and compact structure.The topology of AFPM motor is very rich.Among them,the Yokeless and Segmented Armature(YASA)motor is sought after because the lack of yoke can improve the torque density and material utilization of the motor.However,due to the particularity of YASA structure,there are still some urgent problems to be solved in engineering,such as more efficient magnetic circuit design,more efficient analysis methods,multi-objective optimization design,structural design and strength calculation,heat dissipation problems and so on.Based on the above problems of AFPM motor,this thesis mainly carries out research work from the following four aspects:Firstly,the electromagnetic design scheme of YASA structure AFPM motor is studied.The inner diameter and outer diameter of the motor are calculated by using the size formula of the axial motor.According to the theory of winding coefficient,winding distribution symmetry and cogging torque,two different pole-slot combinations of 16P18S and 20P18S are determined.The stator core size and winding parameters are calculated by the stator size formula and winding formula of YASA structure.Three different rotor structures of Halbach array,built-in and surface mounted are studied to determine the range of pole arc coefficient of permanent magnet.Under the premise that the air gap length and the ratio of inner and outer diameters of the motor are selected,the no-load and load performance based on the 16P18S electromagnetic scheme proves that the two-dimensional analysis method of AFPM motor has approximate substitution for the three-dimensional analysis method.Secondly,the back electromotive force,cogging torque,current density and rotor core thickness of the motor under two pole-slot combinations are analyzed to determine the optimal pole-slot combination.The Latin hypercube sampling method is used to analyze the sensitivity of the parameters such as the optimal slot width,the permanent magnet pole arc coefficient,the rotor core thickness,and the air gap length.The response surface models of back electromotive force,torque and cogging torque are established.The multi-objective performance optimization of back electromotive force,torque,cogging torque and motor current density is realized by evolutionary algorithm.Then,the structure of YASA motor parts is designed.The minimum shaft diameter of the shaft is calculated according to the stiffness and strength formula of the shaft.The stress of the keyway is reduced by changing the structural parameters of the shaft,and the stress concentration is slowed down by setting the fillet at the shoulder position.The PEEK material is selected to make the stator bracket,and the reliability of the material is verified based on the asymmetry of the air gap of the motor.The normalized model of the deformation of the stator and rotor brackets is established,and the size of the stator and rotor brackets is determined by combining the unevenness of the air gap.The structure of the transition parts and the end cover is designed to complete the assembly design of the motor.Finally,the heat dissipation capacity of the motor is analyzed and improved.The heat source of the motor is determined by calculating the loss of the stator core,stator winding and rotor of the motor.Based on the fluid-solid coupling principle,the cooling structure of the circular water pipe around the outer ring of the stator is simulated and calculated.According to the temperature distribution law of the motor,the circular water pipe is improved into two different special-shaped(square)water pipes and closely around the stator winding.By comparing the temperature distribution of the stator and the inlet and outlet pressure of the water pipe under the two structures,the water pipe structure with the best cooling effect is selected on the premise of considering economy and practicability.更多还原